Elahi S M, Harpin S, Cornaglia E, Talbot B, Elazhary Y
Virology Section, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, Quebec.
Can J Vet Res. 1997 Jan;61(1):34-8.
Antigenic variation among 13 Quebec isolates of bovine viral diarrhea virus (BVDV), 4 reference strains and 2 American isolates were studied by peroxidase-linked antibody assay (PLA assay) and neutralization test (NT). The Quebec strains consisted of 3 isolates before 1993 and 10 isolates from 1993. In the PLA assay, we compared 2 different fixatives, acetone and formalin. Acetone-fixation allowed us to identify 6 groups from amongst the viruses tested. All the Quebec isolates were different from the reference strains. In addition, antigenic variation was detected between Quebec isolates obtained before and during 1993. However, PLA assays performed after formalin fixation did not detect these antigenic variations. Neutralization tests were carried out with 2 polyclonal antibodies (PAb) and 6 monoclonal antibodies (MAb). They were used to classify BVDV strains and isolates into 4 groups and 7 subgroups respectively. In conclusion, we demonstrated that the BVDV isolates from the 1993 outbreak in Quebec are antigenically different from reference strains and from isolates existing in Quebec before 1993. In addition, we have shown that 2 internationally used fixation-methods in PLA assay give different results. The usefulness of each method is discussed.
通过过氧化物酶联抗体测定法（PLA测定法）和中和试验（NT），对13株魁北克牛病毒性腹泻病毒（BVDV）分离株、4株参考毒株和2株美国分离株的抗原变异情况进行了研究。魁北克毒株包括1993年之前的3株分离株和1993年的10株分离株。在PLA测定法中，我们比较了两种不同的固定剂，即丙酮和福尔马林。丙酮固定使我们能够在测试的病毒中识别出6个组。所有魁北克分离株均与参考毒株不同。此外，在1993年之前和期间获得的魁北克分离株之间检测到了抗原变异。然而，福尔马林固定后进行的PLA测定未检测到这些抗原变异。用2种多克隆抗体（PAb）和6种单克隆抗体（MAb）进行了中和试验。它们分别用于将BVDV毒株和分离株分为4个组和7个亚组。总之，我们证明了1993年魁北克疫情中的BVDV分离株在抗原性上与参考毒株以及1993年之前魁北克存在的分离株不同。此外，我们还表明，PLA测定法中两种国际上常用的固定方法给出了不同的结果。对每种方法的实用性进行了讨论。
